A battery charging and discharging test method, device, system and battery management system

Abstract

The present application discloses a battery charge and discharge test method, device, system and battery management system. The battery stack under test is electrically connected to an energy storage inverter, and the battery stack includes a plurality of single battery modules, each of which is integrated with a battery monitoring unit. The method includes: sending a first control instruction group to the energy storage inverter to make the battery stack perform multiple rounds of discharge until the battery stack reaches a fully discharged state; sending a second control instruction group to the energy storage inverter to make the battery stack perform multiple rounds of charging until the battery stack reaches a fully charged state; obtaining the battery status information of the battery stack during the discharge process and the charging process through the battery monitoring unit. No external detection equipment is required, and the obtained sampling data is more stable and reliable, realizing automatic test management and data recording, reducing the need for manual control and personnel consumption, and the energy storage inverter can be set up with multiple channels according to the application scenario, meeting the production test requirements of multiple samples.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a battery charging and discharging test method, device, system and battery management system. Background Art

[0002] For current electrochemical energy storage systems, the evaluation of the current state of the battery is particularly important, among which the accuracy of the battery state of charge (SOC) is an important evaluation indicator. The SOC estimation based on the Kalman filter algorithm requires the hybrid pulse power characteristic (HPPC) experiment of the battery at different temperatures and different SOC states to obtain the model parameters of the battery.

[0003] In the prior art, the test of battery stacks is usually carried out using a high-power charging and discharging cabinet and its supporting battery detection device. The detection device is relatively large and cannot be moved, the procurement cost is high, the application range is narrow, and the collection and installation require a lot of manpower; the equipment itself supports a small number of charging and discharging channels and cannot meet the requirements of testing multiple battery stacks; the test process is relatively fixed, and the adjustment of the process steps takes a long time. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a battery charge and discharge test method, device, system and battery management system to overcome the above problems or at least partially solve the above problems.

[0005] According to one aspect of the present application, a battery charge and discharge test method is provided, wherein a battery stack under test is electrically connected to an energy storage converter, the battery stack comprises a plurality of single battery modules, each of which is integrated with a battery monitoring unit, and the method comprises:

[0006] Sending a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge until the battery stack reaches a fully discharged state;

[0007] Sending a second control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of charging until the battery stack reaches a fully charged state;

[0008] The battery status information of the battery stack during the discharging process and the charging process is obtained through the battery monitoring unit.

[0009] Optionally, sending a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge includes:

[0010] Alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter, each power acquisition instruction and its next adjacent power acquisition stop instruction jointly control a discharge round;

[0011] The sending of a second control instruction group to the energy storage converter so as to enable the battery stack to perform multiple rounds of charging includes:

[0012] The electric energy release instruction and the electric energy release stop instruction are sent alternately to the energy storage converter, and each electric energy release instruction and its next adjacent electric energy release stop instruction jointly control a discharge round.

[0013] Optionally, the alternately sending the power acquisition instruction and the power acquisition stop instruction to the energy storage converter further includes:

[0014] After sending a stop power acquisition instruction, if the battery stack has not reached a fully discharged state, determining a voltage change rate according to the acquired battery status information, and sending a next power acquisition instruction if the voltage change rate is lower than a first threshold;

[0015] The alternately sending the power release instruction and the power release stop instruction to the energy storage converter also includes:

[0016] After sending a stop power release instruction, if the battery stack has not reached a fully charged state, the voltage change rate is determined according to the acquired battery status information, and if the voltage change rate is lower than a second threshold, the next power release instruction is sent.

[0017] Optionally, the alternately sending the power acquisition instruction and the power acquisition stop instruction to the energy storage converter comprises: sending the power acquisition stop instruction when the battery status information triggers a stop condition;

[0018] The alternately sending the power release instruction and the power release stop instruction to the energy storage converter includes: sending the power release stop instruction when the battery status information triggers a stop condition.

[0019] Optionally, the battery status information includes a voltage value and / or a charge amount;

[0020] The stop condition includes: the charge state change of the energy storage converter reaches 5%, or the voltage of the battery stack reaches the cut-off voltage.

[0021] Optionally, the method further comprises, before all steps, determining charging parameters and discharging parameters of the battery stack to be tested;

[0022] The stop condition also includes: the charge amount of the battery stack reaches the charging parameter or the discharging parameter.

[0023] Optionally, the method further includes: controlling the sampling frequency of the battery monitoring unit to be less than 100 ms / time, the voltage sampling accuracy to be less than 3 mv, and the current sampling accuracy to be less than 0.5% FSR through the first control instruction group or the second control instruction group.

[0024] According to one aspect of the present application, a battery charge and discharge test device is provided, the device comprising:

[0025] A discharge control unit, used for sending a first control instruction group to the energy storage converter to make the battery stack perform multiple rounds of discharge until the battery stack reaches a fully discharged state;

[0026] A charging control unit, used for sending a second control instruction group to the energy storage converter, so that the battery stack performs multiple rounds of charging until the battery stack reaches a fully charged state;

[0027] The information acquisition unit is used to obtain the battery status information of the battery stack during the discharge process and the charging process through the battery monitoring unit.

[0028] According to one aspect of the present application, a battery management system capable of executing battery charge and discharge tests is provided, comprising the device as described above, and a battery monitoring unit integrated in a battery module.

[0029] According to one aspect of the present application, a battery charge and discharge test system is provided, comprising the battery management system as described above, and an energy storage converter;

[0030] One end of the energy storage converter is connected to the grid side, and the other end is connected to the battery stack;

[0031] The energy storage converter obtains electric energy from the battery stack in response to the first control instruction group;

[0032] The energy storage converter releases electric energy to the battery stack in response to the second control instruction group.

[0033] From the above, it can be seen that the technical solution of the present application, the battery stack includes multiple single battery modules, each of which is integrated with a battery monitoring unit, and no external detection equipment is required, which saves the preliminary sampling preparation work, and the obtained sampling data is more stable and reliable. By electrically connecting the battery stack to be tested with the energy storage inverter, a first control instruction group is sent to the energy storage inverter to make the battery stack perform multiple rounds of discharge until the battery stack reaches a fully discharged state; a second control instruction group is sent to the energy storage inverter to make the battery stack perform multiple rounds of charging until the battery stack reaches a fully charged state; the battery status information of the battery stack during the discharge process and the charging process is obtained through the battery monitoring unit. Automatic test management and data recording are realized, reducing the need for manual control and personnel consumption, and the energy storage inverter can be set up with multiple channels according to the application scenario, meeting the production test needs of multiple samples.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1 A schematic flow chart of a battery charge and discharge test method according to an embodiment of the present application is shown;

[0037] Figure 2 A schematic flow chart of another battery charge and discharge test method according to an embodiment of the present application is shown;

[0038] Figure 3 A schematic structural diagram of a battery charge and discharge test device according to an embodiment of the present application is shown;

[0039] Figure 4 A schematic structural diagram of a battery management system according to an embodiment of the present application is shown;

[0040] Figure 5 A schematic structural diagram of a battery charge and discharge test system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0042] In the technical solution of the present application, the battery stack under test is electrically connected to the energy storage converter, and the battery stack includes a plurality of single cell modules, each of which is integrated with a battery monitoring unit.

[0043] Figure 1 FIG. 1 is a flow chart of a battery charge and discharge test method according to an embodiment of the present application. Figure 1 As shown, the method includes:

[0044] Step S110, sending a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge until the battery stack reaches a fully discharged state.

[0045] In some embodiments of the present application, a first control instruction group is sent to the energy storage inverter, so that the energy storage inverter obtains the electric energy of the battery stack, and the battery stack performs multiple rounds of discharge until the battery stack reaches a fully discharged state. In the case of multiple battery stacks to be tested, the energy storage inverter can test multiple battery stacks to be tested, which can meet the user's needs for production testing of multiple batteries.

[0046] Step S120, sending a second control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of charging until the battery stack reaches a fully charged state.

[0047] In some embodiments of the present application, a second control instruction group is sent to the energy storage inverter to cause the energy storage inverter to release electrical energy to the battery stack, and the battery stack is charged for multiple rounds until the battery stack reaches a fully charged state.

[0048] Step S130, obtaining battery status information of the battery stack during the discharge process and the charge process through the battery monitoring unit.

[0049] In some embodiments of the present application, each single cell module is integrated with a battery monitoring unit, which can realize automatic detection of the battery stack without external detection equipment, saving the preliminary sampling preparation work and making the obtained sampling data more stable and reliable.

[0050] During the discharge and charging process, the battery monitoring unit detects the voltage and current changes of each single battery module in real time, and obtains the battery stack voltage change data during the charging process and the battery stack voltage change data during the discharge process. Based on the obtained battery stack voltage change curves during the discharge and charging processes, the model parameters required by the Kalman filter algorithm are calculated.

[0051] In summary, Figure 1 The technical solution integrates a battery monitoring unit in each single battery module, and can realize automatic detection of the battery stack without external detection equipment, saving the preliminary sampling preparation work and making the obtained sampling data more stable and reliable. By sending a first control instruction group to the energy storage inverter to make the battery stack perform multiple rounds of discharge until the battery stack reaches a fully discharged state, and sending a second control instruction group to the energy storage inverter to make the battery stack perform multiple rounds of charging until the battery stack reaches a fully charged state, the battery monitoring unit is used to obtain the battery status information of the battery stack during the discharge and charging processes, realizing automatic test management and data recording, reducing the need for manual control and personnel consumption, and the energy storage inverter can be set up with multiple channels according to the application scenario, meeting the user's production test needs for multiple batteries.

[0052] In one embodiment of the present application, in the above method, sending a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge includes:

[0053] Alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter, each power acquisition instruction and its next adjacent power acquisition stop instruction jointly control a discharge round;

[0054] Sending a second control instruction group to the energy storage converter to charge the battery stack for multiple rounds includes: sending power release instructions and stop power release instructions to the energy storage converter alternately, and each power release instruction and its next adjacent stop power release instruction jointly control a discharge round.

[0055] In some embodiments of the present application, by sending a power acquisition instruction to the energy storage converter, the energy storage converter is controlled to acquire power from the battery stack, so that the battery stack is discharged. By sending a stop power acquisition instruction to the energy storage converter, the energy storage converter is controlled to stop acquiring power from the battery stack, so that the battery stack stops discharging.

[0056] Send an energy acquisition instruction to the energy storage converter to control the battery stack to start discharging. After sending the energy acquisition instruction, the stop energy acquisition instruction is sent to control the battery stack to stop discharging. The energy acquisition instruction and the next stop energy acquisition instruction adjacent to it jointly control a discharge round. Through multiple rounds of discharge, the battery stack reaches a fully discharged state.

[0057] Similarly, by sending an energy release instruction to the energy storage converter, the energy storage converter is controlled to release energy to the battery stack, so that the battery stack is charged. By sending a stop energy release instruction to the energy storage converter, the energy storage converter is controlled to stop releasing energy to the battery stack, so that the battery stack stops charging.

[0058] Send an energy release command to the energy storage converter to control the battery stack to start charging. After sending the energy release command, the stop energy release command is sent to control the battery stack to stop charging. The energy release command and the next stop energy release command adjacent to it jointly control a discharge round. Through multiple rounds of charging, the battery stack reaches a fully charged state.

[0059] In one embodiment of the present application, in the above method, alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter further includes:

[0060] After sending a stop power acquisition instruction, if the battery stack has not reached a fully discharged state, the voltage change rate is determined according to the acquired battery status information, and if the voltage change rate is lower than a first threshold, the next power acquisition instruction is sent.

[0061] Preferably, the first threshold is set to 1mv / min, that is, the voltage of the single cell module does not change within one minute. During the discharge of the battery stack, the battery monitoring unit monitors the voltage changes of each single cell module in real time. After the energy storage inverter receives the instruction to stop obtaining power, it enters the shutdown state. At this time, if the battery stack has not reached a fully discharged state, the discharge cycle continues. When the battery monitoring unit detects that the voltage change rate of the single cell module is less than 1mv / min, it sends the next power acquisition instruction to the energy storage inverter, so that the energy storage inverter obtains power from the battery stack again and starts the next discharge cycle.

[0062] Alternatingly sending power release instructions and stop power release instructions to the energy storage inverter also includes: after sending a stop power release instruction, if the battery stack has not reached a fully charged state, determining the voltage change rate based on the acquired battery status information, and if the voltage change rate is lower than a second threshold, sending the next power release instruction.

[0063] Preferably, the second threshold is set to 1mv / min, that is, the voltage of the single cell module does not change within one minute. During the charging process of the battery stack, the battery monitoring unit monitors the voltage changes of each single cell module in real time. After the energy storage inverter receives the instruction to stop obtaining power, it enters the shutdown state. At this time, if the battery stack has not reached a fully charged state, the charging round continues. When the battery monitoring unit detects that the voltage change rate of the single cell module is less than 1mv / min, it sends the next power release instruction to the energy storage inverter, so that the energy storage inverter releases power to the battery stack again and starts the next charging round.

[0064] The above technical solution of this embodiment controls the discharge cycle and the charge cycle through the voltage change rate of the single cell module, and realizes the voltage adjustment test step. In addition, when the voltage change rate of the single cell module is less than 1mv / min, the open circuit voltage data of the single cell module can be measured, and the open circuit voltage data measured in this way is more accurate.

[0065] In one embodiment of the present application, in the above method, alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter includes: sending the power acquisition stop instruction when the battery status information triggers the stop condition.

[0066] Alternatingly sending the power release instruction and the power release stop instruction to the energy storage converter includes: sending the power release stop instruction when the battery status information triggers the stop condition.

[0067] In some embodiments of the present application, a stop condition is preset, and when the battery status information triggers the stop condition, a stop power acquisition instruction or a stop power release instruction is sent to control the end of a charging cycle or a discharging cycle.

[0068] In one embodiment of the present application, in the above method, the battery status information includes voltage value and / or charge amount; the stop condition includes: the charge state change of the energy storage converter reaches 5%, or the voltage of the battery stack reaches the cut-off voltage.

[0069] In some embodiments of the present application, during the charging and discharging process of the battery stack, the voltage value or the charge amount of the battery stack is obtained, or both the voltage value and the charge amount are obtained.

[0070] Preferably, the stop condition is preset to the state of charge change of the energy storage converter reaches 5% or the voltage of the battery stack reaches the cut-off voltage. That is, during the discharge process, when the state of charge of the energy storage converter decreases by 5% or the voltage of the battery stack reaches the discharge cut-off voltage, a stop power acquisition instruction is sent to the energy storage converter to cause the energy storage converter to suspend obtaining power from the battery stack. During the charging process, when the state of charge of the energy storage converter increases by 5% or the voltage of the battery stack reaches the charging cut-off voltage, a stop power release instruction is sent to the energy storage converter to cause the energy storage converter to suspend releasing power to the battery stack.

[0071] In one embodiment of the present application, the above method further includes, before all steps, determining the charging parameters and discharging parameters of the battery stack to be tested; the stop condition also includes: the charge amount of the battery stack reaches the charging parameter or the discharging parameter.

[0072] In some embodiments of the present application, before testing the battery stack, the charging parameters and discharging parameters of the battery stack are set. Preferably, the charging parameters include the chargeable capacity C0 of the battery stack, and the discharging parameters include the dischargeable capacity C1 of the battery stack.

[0073] During the discharge of the battery stack, the battery is discharged according to the standard discharge specifications. When the charge of the battery stack reaches the dischargeable capacity, that is, the state of charge reaches 0%, it means that the battery stack has been fully discharged, and the discharge process is terminated. During the charging of the battery stack, the battery is charged according to the standard charging specifications. When the charge of the battery stack reaches the chargeable capacity, that is, the state of charge reaches 100%, it means that the battery stack has been fully charged, and the charging process is terminated.

[0074] Preferably, when the battery stack includes multiple single cell modules, the voltage of the single cell module with the smallest voltage value is used as the discharge voltage of the battery stack, and the voltage of the single cell module with the highest voltage value is used as the charge voltage of the battery stack. During the discharge process, the standard discharge specification can be set to 1C1, that is, constant current discharge is performed at a charge rate of 1C1. During the charging process, the standard discharge specification can be set to 1C0, that is, constant current charging is performed at a charge rate of 1C0.

[0075] In one embodiment of the present application, the above method also includes: controlling the sampling frequency of the battery monitoring unit to less than 100ms / time, the voltage sampling accuracy to within 3mv, and the current sampling accuracy to 0.5%FSR through the first control instruction group or the second control instruction group.

[0076] In some embodiments of the present application, the battery stack is discharged or charged for multiple rounds through the first control instruction or the second control instruction group to complete the charging process or the discharging process, so that the sampling frequency of the battery monitoring unit is controlled below 100ms / time, the voltage sampling accuracy is controlled within 3mv, and the current sampling accuracy is controlled within 0.5%FSR. Compared with the prior art, the sampling frequency and sampling accuracy are improved, making the acquired sampling data more reliable.

[0077] Figure 2 FIG. 2 is a flow chart of another battery charge and discharge test method according to an embodiment of the present application. Figure 2 As shown, the method includes two stages: a pre-test preparation stage and a test stage.

[0078] The pre-test preparation stage includes steps S210 to S220.

[0079] Step S210, presetting the chargeable capacity C0 and the dischargeable capacity C1 of the battery pack.

[0080] Step S220, start the energy storage converter to charge the battery stack. Send an energy release instruction to the energy storage converter, and the energy storage current meter charges the battery stack with a constant current of 1C0. The charge amount of the battery stack obtains the rechargeable capacity. When the SOC is calibrated to 100%, charging is stopped and the battery management system enters the shutdown state. During the charging process, the battery monitoring unit monitors the voltage of the single battery module in real time. When the voltage variable is less than 1mv / min, it sends an energy acquisition instruction to the energy storage converter to enter the test phase.

[0081] When the battery stack includes a plurality of single cell modules, the voltage of the single cell module with the smallest voltage value is used as the discharge voltage of the battery stack, and the voltage of the single cell module with the highest voltage value is used as the charge voltage of the battery stack.

[0082] The testing phase includes steps S230 to S250.

[0083] Step S230, the discharge test process, includes steps S2301 to S2304.

[0084] Step S2301, after the battery stack is fully charged in step S220, an electric energy acquisition instruction is sent to the energy storage converter, so that the energy storage converter performs constant current discharge with a 1C1 current.

[0085] Step S2302: When the rated SOC of the battery stack decreases by 5% or the voltage of the battery stack reaches the discharge cut-off voltage, a stop power acquisition instruction is sent to the energy storage inverter to make the energy storage inverter stop acquiring power from the battery stack.

[0086] Step S2303, the battery monitoring unit monitors the voltage of each single cell module in real time and stores it. When the voltage change rate of the single cell module with the smallest voltage value is less than 1mv / min, the next power acquisition instruction is sent to the energy storage inverter, so that the energy storage inverter enters the working state again and obtains power from the battery stack.

[0087] In step S2304, the stop power acquisition instruction in step S2302 and the power acquisition instruction in step S2303 jointly control a discharge cycle. After 21 cycles, the charge of the battery stack reaches the dischargeable capacity, that is, the calibrated SOC of the battery stack is 0%, which means that the battery stack has been fully discharged, and the discharge process ends, and the charging process step S240 is entered.

[0088] Step S240, charging test process, includes steps S2401 to S2404.

[0089] Step S2401, after the battery stack is discharged through step S230, an energy release instruction is sent to the energy storage converter to enable the energy storage converter to perform constant current charging with a 1C0 current.

[0090] Step S2402, when the calibrated SOC of the battery stack increases by 5% or the voltage of the battery stack reaches the charging cut-off voltage, a stop power release instruction is sent to the energy storage inverter to make the energy storage inverter stop releasing power to the battery stack.

[0091] Step S2403, the battery monitoring unit monitors the voltage of each single cell module in real time and stores it. When the voltage change rate of the single cell module with the smallest voltage value is less than 1mv / min, the next power release instruction is sent to the energy storage inverter, so that the energy storage inverter enters the working state and releases power to the battery stack.

[0092] Step S2404, the stop power release instruction in step S2402 and the power release instruction in step S2403 jointly control a charging cycle. After 21 cycles, the charge of the battery stack reaches the dischargeable capacity, that is, the calibrated SOC of the battery stack is 100%, which means that the battery stack has been fully charged, and the charging process ends, and enters the charging process step S250.

[0093] Step S250, result output.

[0094] During the charging and discharging processes, a discharge cycle is controlled by the power acquisition instruction and the power acquisition stop instruction to control the discharge process, and a charging cycle is controlled by the power release instruction and the power release stop instruction to control the charging process, so that the sampling frequency of the battery monitoring unit is controlled below 100ms / time, the voltage sampling accuracy is controlled within 3mv, and the current sampling accuracy is controlled within 0.5%FSR. Compared with the existing technology, the sampling frequency and sampling accuracy are improved, making the obtained sampling data more reliable.

[0095] During the charging and discharging process, the battery monitoring unit samples and stores the voltage and current of each single battery module in real time according to the above sampling frequency and sampling accuracy. After the charging and discharging process is completed, the output sampling obtains the battery stack voltage change data during the discharge process and the battery stack voltage change data during the charging process.

[0096] Figure 3 FIG. 1 is a schematic diagram showing the structure of a battery charge and discharge test device according to an embodiment of the present application. Figure 3 As shown, the battery charge and discharge test device 300 includes:

[0097] The discharge control unit 310 is used to send a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge until the battery stack reaches a fully discharged state.

[0098] The charging control unit 320 is used to send a second control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of charging until the battery stack reaches a fully charged state.

[0099] The information acquisition unit 330 is used to obtain the battery status information of the battery stack during the discharge process and the charging process through the battery monitoring unit.

[0100] In one embodiment of the present application, in the above-mentioned device, the discharge control unit 310 is used to alternately send power acquisition instructions and stop power acquisition instructions to the energy storage inverter, and each power acquisition instruction and its next adjacent stop power acquisition instruction jointly control a discharge round.

[0101] The charging control unit 320 is used to send power release instructions and power release stop instructions to the energy storage converter alternately, and each power release instruction and its next adjacent power release stop instruction jointly control a discharge round.

[0102] In one embodiment of the present application, in the above-mentioned device, the discharge control unit 310 is used to determine the voltage change rate based on the acquired battery status information after sending a stop power acquisition instruction if the battery stack has not reached a fully discharged state, and if the voltage change rate is lower than a first threshold, send the next power acquisition instruction.

[0103] The charging control unit 320 is used to determine the voltage change rate according to the acquired battery status information if the battery stack has not reached a fully charged state after sending a stop power release instruction, and if the voltage change rate is lower than a second threshold, send the next power release instruction. In one embodiment of the present application, in the above-mentioned device, the discharging control unit 310 is used to send a stop power acquisition instruction when the battery status information triggers a stop condition.

[0104] The charging control unit 320 is used to send an instruction to stop releasing electric energy when the battery status information triggers a stop condition.

[0105] In one embodiment of the present application, the battery status information in the above-mentioned device 300 includes a voltage value and / or a charge amount;

[0106] The stopping conditions include: the charge state change of the energy storage converter reaches 5%, or the voltage of the battery stack reaches the cut-off voltage.

[0107] In one embodiment of the present application, the above-mentioned device further includes a preset unit, which is used to determine the charging parameters and the discharging parameters of the battery stack to be tested;

[0108] The stop condition in the battery charge and discharge test device 300 also includes: the charge amount of the battery stack reaches a charging parameter or a discharging parameter.

[0109] In one embodiment of the present application, in the above-mentioned device, the information acquisition unit 330 is used to control the sampling frequency of the battery monitoring unit to less than 100ms / time, the voltage sampling accuracy to within 3mv, and the current sampling accuracy to 0.5%FSR through the first control instruction group or the second control instruction group.

[0110] Figure 4 FIG. 1 is a schematic diagram showing a battery management system that can perform battery charge and discharge testing according to an embodiment of the present application. Figure 4 As shown, the battery management system 400 includes the battery charge and discharge test device 300 and a battery monitoring unit 410 integrated in a battery module.

[0111] Figure 5 FIG. 1 is a schematic diagram showing the structure of a battery charge and discharge test system according to an embodiment of the present application. Figure 5 As shown, the battery charge and discharge test system 500 includes the above-mentioned battery management system 400 and an energy storage converter 510 .

[0112] One end of the energy storage converter 510 is connected to the grid side, and the other end is connected to the battery stack in the battery management system 400;

[0113] The energy storage converter 510 obtains electric energy from the battery stack in response to the first control instruction group;

[0114] The energy storage converter 510 releases electrical energy to the battery stack in response to the second control instruction group.

[0115] It should be noted that the specific implementation of the above-mentioned device and system embodiments can be carried out with reference to the specific implementation of the above-mentioned corresponding method embodiments, which will not be repeated here.

[0116] In summary, the technical solution of the present application integrates a battery monitoring unit in each single battery module, sends a first control instruction group to the energy storage converter, so that the battery stack performs multiple rounds of discharge until the battery stack reaches a fully discharged state, sends a second control instruction group to the energy storage converter, so that the battery stack performs multiple rounds of charging until the battery stack reaches a fully charged state, and uses the battery monitoring unit to obtain the battery status information of the battery stack during the discharge process and the charging process. Without the need for external detection equipment, automatic detection of the battery stack can be achieved, saving the preliminary sampling preparation work, and the obtained sampling data is more stable. The sampling accuracy and sampling frequency are improved, making the obtained sampling data more reliable. At the same time, automatic test management and data recording are realized, reducing the need for manual control and personnel consumption, and realizing the voltage adjustment process step, which is more flexible and simple, improves the test efficiency and accuracy, and can also obtain more accurate open circuit voltage data. In addition, the energy storage converter can be set up with multiple channels according to the application scenario, meeting the production test requirements of multiple samples. In different application scenarios, multiple systems 500 can also be connected in parallel to expand the scope of use.

[0117] The above is only a specific implementation of the present application. Under the above teachings of the present application, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is only to better explain the purpose of the present application, and the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A battery charge and discharge test method, characterized in that: The battery stack to be tested is electrically connected to the energy storage converter, the battery stack includes a plurality of single battery modules, each of which is integrated with a battery monitoring unit, and the method includes: Sending a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge until the battery stack reaches a fully discharged state; Sending a second control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of charging until the battery stack reaches a fully charged state; Acquiring battery status information of the battery stack during the discharge process and the charging process through the battery monitoring unit; The sending of a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge includes: Alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter, each power acquisition instruction and its next adjacent power acquisition stop instruction jointly control a discharge round; The sending of a second control instruction group to the energy storage converter so as to enable the battery stack to perform multiple rounds of charging includes: Alternately sending power release instructions and power release stop instructions to the energy storage converter, each power release instruction and its next adjacent power release stop instruction jointly control a charging round; The alternately sending the power acquisition instruction and the power acquisition stop instruction to the energy storage converter also includes: After sending a stop power acquisition instruction, if the battery stack has not reached a fully discharged state, determining a voltage change rate according to the acquired battery status information, and sending a next power acquisition instruction if the voltage change rate is lower than a first threshold; The alternately sending the power release instruction and the power release stop instruction to the energy storage converter also includes: After sending a stop power release instruction, if the battery stack has not reached a fully charged state, the voltage change rate is determined according to the acquired battery status information, and if the voltage change rate is lower than a second threshold, the next power release instruction is sent.

2. The method according to claim 1, characterized in that The alternately sending the power acquisition instruction and the power acquisition stop instruction to the energy storage converter comprises: sending the power acquisition stop instruction when the battery status information triggers the stop condition; The alternately sending the power release instruction and the power release stop instruction to the energy storage converter includes: sending the power release stop instruction when the battery status information triggers a stop condition.

3. The method according to claim 2, characterized in that The battery status information includes voltage value and / or charge amount; The stop condition includes: the charge state change of the energy storage converter reaches 5%, or the voltage of the battery stack reaches the cut-off voltage.

4. The method according to claim 2 or 3, characterized in that The method further comprises, before all steps, determining charging parameters and discharging parameters of the battery stack to be tested; The stop condition also includes: the charge amount of the battery stack reaches the charging parameter or the discharging parameter.

5. The method according to claim 1, characterized in that The method further includes: controlling the sampling frequency of the battery monitoring unit to be less than 100ms / time, the voltage sampling accuracy to be less than 3mv, and the current sampling accuracy to be less than 0.5%FSR through the first control instruction group or the second control instruction group.

6. A battery charge and discharge test device, characterized in that: The device comprises: A discharge control unit, used for sending a first control instruction group to the energy storage converter to make the battery stack perform multiple rounds of discharge until the battery stack reaches a fully discharged state; A charging control unit, used for sending a second control instruction group to the energy storage converter, so that the battery stack performs multiple rounds of charging until the battery stack reaches a fully charged state; An information collection unit, used to obtain battery status information of the battery stack during the discharge process and the charging process through the battery monitoring unit; The sending of a first control instruction group to the energy storage converter to enable the battery stack to perform multiple rounds of discharge includes: Alternately sending power acquisition instructions and power acquisition stop instructions to the energy storage converter, each power acquisition instruction and its next adjacent power acquisition stop instruction jointly control a discharge round; The sending of a second control instruction group to the energy storage converter so as to enable the battery stack to perform multiple rounds of charging includes: Alternately sending power release instructions and power release stop instructions to the energy storage converter, each power release instruction and its next adjacent power release stop instruction jointly control a charging round; The alternately sending the power acquisition instruction and the power acquisition stop instruction to the energy storage converter also includes: After sending a stop power acquisition instruction, if the battery stack has not reached a fully discharged state, determining a voltage change rate according to the acquired battery status information, and sending a next power acquisition instruction if the voltage change rate is lower than a first threshold; The alternately sending the power release instruction and the power release stop instruction to the energy storage converter also includes: After sending a stop power release instruction, if the battery stack has not reached a fully charged state, the voltage change rate is determined according to the acquired battery status information, and if the voltage change rate is lower than a second threshold, the next power release instruction is sent.

7. A battery management system capable of executing battery charge and discharge tests, comprising the device as claimed in claim 6, and a battery monitoring unit integrated in a battery module.

8. A battery charge and discharge test system, comprising the battery management system as claimed in claim 7, and an energy storage converter; One end of the energy storage converter is connected to the grid side, and the other end is connected to the battery stack; The energy storage converter obtains electric energy from the battery stack in response to the first control instruction group; The energy storage converter releases electric energy to the battery stack in response to a second control instruction group.

Images